1. Technical Field
The present invention relates to an aerial photograph data set in which aerial photographs obtained by aerial photography is rearranged according to a specific system, a method for creating the same, and a method for displaying the same.
2. Background Technology
Conventionally, aerial photography is used for photogrammetry to perform topographical mapping, industrial surveying, surveying of cultural assets, natural disaster surveying, and the like. Aerial photography is generally performed with a certain endlap ratio and sidelap ratio so that captured images overlap both laterally and longitudinally. While this is done to avoid missing areas during imaging, in recent times there has also been an active use of overlapped areas in the captured images.
For example, in Japanese Laid-Open Patent Publication Number 2005-156514, there is an flight direction and a direction that crosses the flight direction that is perpendicular. Overlapping imaging is performed with the overlap ratio in both the flight direction and the cross direction perpendicular thereto set to about 60%. All overlapping images that contain a certain object image are selected, and the overlapping sections are arranged in the overlapping direction around an image in which the object image is positioned at the center, forming a matrix of 9 images. This creates an aerial photography image set.
While the conventional image set known in the patent publication and the like is very useful compared to prior image sets. However, because of problems such as a limited scope of applications and inadequate field of view and accuracy, there has been a need for photographic image data sets with further improvements.
For example, the patent publication and the like could only be used in limited applications because other sites besides the site directly below the principal imaging point, i.e., the imaging center, could not be used as a target point. Also, as to other conventional methods, the needs required for an aerial photograph data set would not be satisfied because of required significant time and huge expenses for aerial photographic imaging and image processing, by making the methods impractical. The visibility (ease of viewing) and handling was also inadequate.
Furthermore, with the conventional methods, when the imaging object is a structure such as a building, the tilt of the building is unstable or the side surfaces of the building or the like could not be adequately observed or the state of horizontally continuous land surfaces could not be observed, and the like.
Also, with the conventional methods, there are aerial photography Image data sets in which the overlapping imaging of a target is managed according to flight time intervals of the flight course, but there is no management of the direction (e.g., the perpendicular direction) intersecting with air flight direction (flight direction), making the data difficult to handle in practical use. There is also a need to make use of past data obtained with this type of conventional method as well. Alternatively, there are still imaging methods being used that involve irregular imaging positions. There is a need for aerial photography image data sets and a method for creating the same in these cases as well. Furthermore, if an aerial photograph data set is created after significant effort, there is still the need to have an improved displaying method. There is a need to a displaying method that is easy to see, easy to handle, that allows various measurements to be made easily, and the like.